Tom,
We don't use so much radioactivity, but a year's experience with
Redivue is a positive one. We use both dCTP and gamma-ATP (32P),
as well as dATP and gamma-ATP (33P). The former are usually used up in
two weeks, the 33P labelled often in a month storage at RT, and still
keep well. Using the dispencer is not practical for our scale.
I did not make PEI tests, but had no failures either.
( Should I say "no connection to Amersham"?)
Cheers,